| /* | 
 |  * Copyright 2014 Advanced Micro Devices, Inc. | 
 |  * | 
 |  * Permission is hereby granted, free of charge, to any person obtaining a | 
 |  * copy of this software and associated documentation files (the "Software"), | 
 |  * to deal in the Software without restriction, including without limitation | 
 |  * the rights to use, copy, modify, merge, publish, distribute, sublicense, | 
 |  * and/or sell copies of the Software, and to permit persons to whom the | 
 |  * Software is furnished to do so, subject to the following conditions: | 
 |  * | 
 |  * The above copyright notice and this permission notice shall be included in | 
 |  * all copies or substantial portions of the Software. | 
 |  * | 
 |  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR | 
 |  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, | 
 |  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL | 
 |  * THE COPYRIGHT HOLDER(S) OR AUTHOR(S) BE LIABLE FOR ANY CLAIM, DAMAGES OR | 
 |  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, | 
 |  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR | 
 |  * OTHER DEALINGS IN THE SOFTWARE. | 
 |  * | 
 |  */ | 
 | #include <drm/drmP.h> | 
 | #include <drm/amdgpu_drm.h> | 
 | #include "amdgpu.h" | 
 | #include "atom.h" | 
 | #include "atombios_encoders.h" | 
 | #include "amdgpu_pll.h" | 
 | #include <asm/div64.h> | 
 | #include <linux/gcd.h> | 
 |  | 
 | /** | 
 |  * amdgpu_pll_reduce_ratio - fractional number reduction | 
 |  * | 
 |  * @nom: nominator | 
 |  * @den: denominator | 
 |  * @nom_min: minimum value for nominator | 
 |  * @den_min: minimum value for denominator | 
 |  * | 
 |  * Find the greatest common divisor and apply it on both nominator and | 
 |  * denominator, but make nominator and denominator are at least as large | 
 |  * as their minimum values. | 
 |  */ | 
 | static void amdgpu_pll_reduce_ratio(unsigned *nom, unsigned *den, | 
 | 				    unsigned nom_min, unsigned den_min) | 
 | { | 
 | 	unsigned tmp; | 
 |  | 
 | 	/* reduce the numbers to a simpler ratio */ | 
 | 	tmp = gcd(*nom, *den); | 
 | 	*nom /= tmp; | 
 | 	*den /= tmp; | 
 |  | 
 | 	/* make sure nominator is large enough */ | 
 | 	if (*nom < nom_min) { | 
 | 		tmp = DIV_ROUND_UP(nom_min, *nom); | 
 | 		*nom *= tmp; | 
 | 		*den *= tmp; | 
 | 	} | 
 |  | 
 | 	/* make sure the denominator is large enough */ | 
 | 	if (*den < den_min) { | 
 | 		tmp = DIV_ROUND_UP(den_min, *den); | 
 | 		*nom *= tmp; | 
 | 		*den *= tmp; | 
 | 	} | 
 | } | 
 |  | 
 | /** | 
 |  * amdgpu_pll_get_fb_ref_div - feedback and ref divider calculation | 
 |  * | 
 |  * @nom: nominator | 
 |  * @den: denominator | 
 |  * @post_div: post divider | 
 |  * @fb_div_max: feedback divider maximum | 
 |  * @ref_div_max: reference divider maximum | 
 |  * @fb_div: resulting feedback divider | 
 |  * @ref_div: resulting reference divider | 
 |  * | 
 |  * Calculate feedback and reference divider for a given post divider. Makes | 
 |  * sure we stay within the limits. | 
 |  */ | 
 | static void amdgpu_pll_get_fb_ref_div(unsigned nom, unsigned den, unsigned post_div, | 
 | 				      unsigned fb_div_max, unsigned ref_div_max, | 
 | 				      unsigned *fb_div, unsigned *ref_div) | 
 | { | 
 | 	/* limit reference * post divider to a maximum */ | 
 | 	ref_div_max = min(128 / post_div, ref_div_max); | 
 |  | 
 | 	/* get matching reference and feedback divider */ | 
 | 	*ref_div = min(max(DIV_ROUND_CLOSEST(den, post_div), 1u), ref_div_max); | 
 | 	*fb_div = DIV_ROUND_CLOSEST(nom * *ref_div * post_div, den); | 
 |  | 
 | 	/* limit fb divider to its maximum */ | 
 | 	if (*fb_div > fb_div_max) { | 
 | 		*ref_div = DIV_ROUND_CLOSEST(*ref_div * fb_div_max, *fb_div); | 
 | 		*fb_div = fb_div_max; | 
 | 	} | 
 | } | 
 |  | 
 | /** | 
 |  * amdgpu_pll_compute - compute PLL paramaters | 
 |  * | 
 |  * @pll: information about the PLL | 
 |  * @dot_clock_p: resulting pixel clock | 
 |  * fb_div_p: resulting feedback divider | 
 |  * frac_fb_div_p: fractional part of the feedback divider | 
 |  * ref_div_p: resulting reference divider | 
 |  * post_div_p: resulting reference divider | 
 |  * | 
 |  * Try to calculate the PLL parameters to generate the given frequency: | 
 |  * dot_clock = (ref_freq * feedback_div) / (ref_div * post_div) | 
 |  */ | 
 | void amdgpu_pll_compute(struct amdgpu_pll *pll, | 
 | 			u32 freq, | 
 | 			u32 *dot_clock_p, | 
 | 			u32 *fb_div_p, | 
 | 			u32 *frac_fb_div_p, | 
 | 			u32 *ref_div_p, | 
 | 			u32 *post_div_p) | 
 | { | 
 | 	unsigned target_clock = pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV ? | 
 | 		freq : freq / 10; | 
 |  | 
 | 	unsigned fb_div_min, fb_div_max, fb_div; | 
 | 	unsigned post_div_min, post_div_max, post_div; | 
 | 	unsigned ref_div_min, ref_div_max, ref_div; | 
 | 	unsigned post_div_best, diff_best; | 
 | 	unsigned nom, den; | 
 |  | 
 | 	/* determine allowed feedback divider range */ | 
 | 	fb_div_min = pll->min_feedback_div; | 
 | 	fb_div_max = pll->max_feedback_div; | 
 |  | 
 | 	if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV) { | 
 | 		fb_div_min *= 10; | 
 | 		fb_div_max *= 10; | 
 | 	} | 
 |  | 
 | 	/* determine allowed ref divider range */ | 
 | 	if (pll->flags & AMDGPU_PLL_USE_REF_DIV) | 
 | 		ref_div_min = pll->reference_div; | 
 | 	else | 
 | 		ref_div_min = pll->min_ref_div; | 
 |  | 
 | 	if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV && | 
 | 	    pll->flags & AMDGPU_PLL_USE_REF_DIV) | 
 | 		ref_div_max = pll->reference_div; | 
 | 	else | 
 | 		ref_div_max = pll->max_ref_div; | 
 |  | 
 | 	/* determine allowed post divider range */ | 
 | 	if (pll->flags & AMDGPU_PLL_USE_POST_DIV) { | 
 | 		post_div_min = pll->post_div; | 
 | 		post_div_max = pll->post_div; | 
 | 	} else { | 
 | 		unsigned vco_min, vco_max; | 
 |  | 
 | 		if (pll->flags & AMDGPU_PLL_IS_LCD) { | 
 | 			vco_min = pll->lcd_pll_out_min; | 
 | 			vco_max = pll->lcd_pll_out_max; | 
 | 		} else { | 
 | 			vco_min = pll->pll_out_min; | 
 | 			vco_max = pll->pll_out_max; | 
 | 		} | 
 |  | 
 | 		if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV) { | 
 | 			vco_min *= 10; | 
 | 			vco_max *= 10; | 
 | 		} | 
 |  | 
 | 		post_div_min = vco_min / target_clock; | 
 | 		if ((target_clock * post_div_min) < vco_min) | 
 | 			++post_div_min; | 
 | 		if (post_div_min < pll->min_post_div) | 
 | 			post_div_min = pll->min_post_div; | 
 |  | 
 | 		post_div_max = vco_max / target_clock; | 
 | 		if ((target_clock * post_div_max) > vco_max) | 
 | 			--post_div_max; | 
 | 		if (post_div_max > pll->max_post_div) | 
 | 			post_div_max = pll->max_post_div; | 
 | 	} | 
 |  | 
 | 	/* represent the searched ratio as fractional number */ | 
 | 	nom = target_clock; | 
 | 	den = pll->reference_freq; | 
 |  | 
 | 	/* reduce the numbers to a simpler ratio */ | 
 | 	amdgpu_pll_reduce_ratio(&nom, &den, fb_div_min, post_div_min); | 
 |  | 
 | 	/* now search for a post divider */ | 
 | 	if (pll->flags & AMDGPU_PLL_PREFER_MINM_OVER_MAXP) | 
 | 		post_div_best = post_div_min; | 
 | 	else | 
 | 		post_div_best = post_div_max; | 
 | 	diff_best = ~0; | 
 |  | 
 | 	for (post_div = post_div_min; post_div <= post_div_max; ++post_div) { | 
 | 		unsigned diff; | 
 | 		amdgpu_pll_get_fb_ref_div(nom, den, post_div, fb_div_max, | 
 | 					  ref_div_max, &fb_div, &ref_div); | 
 | 		diff = abs(target_clock - (pll->reference_freq * fb_div) / | 
 | 			(ref_div * post_div)); | 
 |  | 
 | 		if (diff < diff_best || (diff == diff_best && | 
 | 		    !(pll->flags & AMDGPU_PLL_PREFER_MINM_OVER_MAXP))) { | 
 |  | 
 | 			post_div_best = post_div; | 
 | 			diff_best = diff; | 
 | 		} | 
 | 	} | 
 | 	post_div = post_div_best; | 
 |  | 
 | 	/* get the feedback and reference divider for the optimal value */ | 
 | 	amdgpu_pll_get_fb_ref_div(nom, den, post_div, fb_div_max, ref_div_max, | 
 | 				  &fb_div, &ref_div); | 
 |  | 
 | 	/* reduce the numbers to a simpler ratio once more */ | 
 | 	/* this also makes sure that the reference divider is large enough */ | 
 | 	amdgpu_pll_reduce_ratio(&fb_div, &ref_div, fb_div_min, ref_div_min); | 
 |  | 
 | 	/* avoid high jitter with small fractional dividers */ | 
 | 	if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV && (fb_div % 10)) { | 
 | 		fb_div_min = max(fb_div_min, (9 - (fb_div % 10)) * 20 + 60); | 
 | 		if (fb_div < fb_div_min) { | 
 | 			unsigned tmp = DIV_ROUND_UP(fb_div_min, fb_div); | 
 | 			fb_div *= tmp; | 
 | 			ref_div *= tmp; | 
 | 		} | 
 | 	} | 
 |  | 
 | 	/* and finally save the result */ | 
 | 	if (pll->flags & AMDGPU_PLL_USE_FRAC_FB_DIV) { | 
 | 		*fb_div_p = fb_div / 10; | 
 | 		*frac_fb_div_p = fb_div % 10; | 
 | 	} else { | 
 | 		*fb_div_p = fb_div; | 
 | 		*frac_fb_div_p = 0; | 
 | 	} | 
 |  | 
 | 	*dot_clock_p = ((pll->reference_freq * *fb_div_p * 10) + | 
 | 			(pll->reference_freq * *frac_fb_div_p)) / | 
 | 		       (ref_div * post_div * 10); | 
 | 	*ref_div_p = ref_div; | 
 | 	*post_div_p = post_div; | 
 |  | 
 | 	DRM_DEBUG_KMS("%d - %d, pll dividers - fb: %d.%d ref: %d, post %d\n", | 
 | 		      freq, *dot_clock_p * 10, *fb_div_p, *frac_fb_div_p, | 
 | 		      ref_div, post_div); | 
 | } | 
 |  | 
 | /** | 
 |  * amdgpu_pll_get_use_mask - look up a mask of which pplls are in use | 
 |  * | 
 |  * @crtc: drm crtc | 
 |  * | 
 |  * Returns the mask of which PPLLs (Pixel PLLs) are in use. | 
 |  */ | 
 | u32 amdgpu_pll_get_use_mask(struct drm_crtc *crtc) | 
 | { | 
 | 	struct drm_device *dev = crtc->dev; | 
 | 	struct drm_crtc *test_crtc; | 
 | 	struct amdgpu_crtc *test_amdgpu_crtc; | 
 | 	u32 pll_in_use = 0; | 
 |  | 
 | 	list_for_each_entry(test_crtc, &dev->mode_config.crtc_list, head) { | 
 | 		if (crtc == test_crtc) | 
 | 			continue; | 
 |  | 
 | 		test_amdgpu_crtc = to_amdgpu_crtc(test_crtc); | 
 | 		if (test_amdgpu_crtc->pll_id != ATOM_PPLL_INVALID) | 
 | 			pll_in_use |= (1 << test_amdgpu_crtc->pll_id); | 
 | 	} | 
 | 	return pll_in_use; | 
 | } | 
 |  | 
 | /** | 
 |  * amdgpu_pll_get_shared_dp_ppll - return the PPLL used by another crtc for DP | 
 |  * | 
 |  * @crtc: drm crtc | 
 |  * | 
 |  * Returns the PPLL (Pixel PLL) used by another crtc/encoder which is | 
 |  * also in DP mode.  For DP, a single PPLL can be used for all DP | 
 |  * crtcs/encoders. | 
 |  */ | 
 | int amdgpu_pll_get_shared_dp_ppll(struct drm_crtc *crtc) | 
 | { | 
 | 	struct drm_device *dev = crtc->dev; | 
 | 	struct drm_crtc *test_crtc; | 
 | 	struct amdgpu_crtc *test_amdgpu_crtc; | 
 |  | 
 | 	list_for_each_entry(test_crtc, &dev->mode_config.crtc_list, head) { | 
 | 		if (crtc == test_crtc) | 
 | 			continue; | 
 | 		test_amdgpu_crtc = to_amdgpu_crtc(test_crtc); | 
 | 		if (test_amdgpu_crtc->encoder && | 
 | 		    ENCODER_MODE_IS_DP(amdgpu_atombios_encoder_get_encoder_mode(test_amdgpu_crtc->encoder))) { | 
 | 			/* for DP use the same PLL for all */ | 
 | 			if (test_amdgpu_crtc->pll_id != ATOM_PPLL_INVALID) | 
 | 				return test_amdgpu_crtc->pll_id; | 
 | 		} | 
 | 	} | 
 | 	return ATOM_PPLL_INVALID; | 
 | } | 
 |  | 
 | /** | 
 |  * amdgpu_pll_get_shared_nondp_ppll - return the PPLL used by another non-DP crtc | 
 |  * | 
 |  * @crtc: drm crtc | 
 |  * @encoder: drm encoder | 
 |  * | 
 |  * Returns the PPLL (Pixel PLL) used by another non-DP crtc/encoder which can | 
 |  * be shared (i.e., same clock). | 
 |  */ | 
 | int amdgpu_pll_get_shared_nondp_ppll(struct drm_crtc *crtc) | 
 | { | 
 | 	struct amdgpu_crtc *amdgpu_crtc = to_amdgpu_crtc(crtc); | 
 | 	struct drm_device *dev = crtc->dev; | 
 | 	struct drm_crtc *test_crtc; | 
 | 	struct amdgpu_crtc *test_amdgpu_crtc; | 
 | 	u32 adjusted_clock, test_adjusted_clock; | 
 |  | 
 | 	adjusted_clock = amdgpu_crtc->adjusted_clock; | 
 |  | 
 | 	if (adjusted_clock == 0) | 
 | 		return ATOM_PPLL_INVALID; | 
 |  | 
 | 	list_for_each_entry(test_crtc, &dev->mode_config.crtc_list, head) { | 
 | 		if (crtc == test_crtc) | 
 | 			continue; | 
 | 		test_amdgpu_crtc = to_amdgpu_crtc(test_crtc); | 
 | 		if (test_amdgpu_crtc->encoder && | 
 | 		    !ENCODER_MODE_IS_DP(amdgpu_atombios_encoder_get_encoder_mode(test_amdgpu_crtc->encoder))) { | 
 | 			/* check if we are already driving this connector with another crtc */ | 
 | 			if (test_amdgpu_crtc->connector == amdgpu_crtc->connector) { | 
 | 				/* if we are, return that pll */ | 
 | 				if (test_amdgpu_crtc->pll_id != ATOM_PPLL_INVALID) | 
 | 					return test_amdgpu_crtc->pll_id; | 
 | 			} | 
 | 			/* for non-DP check the clock */ | 
 | 			test_adjusted_clock = test_amdgpu_crtc->adjusted_clock; | 
 | 			if ((crtc->mode.clock == test_crtc->mode.clock) && | 
 | 			    (adjusted_clock == test_adjusted_clock) && | 
 | 			    (amdgpu_crtc->ss_enabled == test_amdgpu_crtc->ss_enabled) && | 
 | 			    (test_amdgpu_crtc->pll_id != ATOM_PPLL_INVALID)) | 
 | 				return test_amdgpu_crtc->pll_id; | 
 | 		} | 
 | 	} | 
 | 	return ATOM_PPLL_INVALID; | 
 | } |